Dryer with temperature varying air flow restriction plate



Nov. 4, 1969 N, J. WORKMAN 3,475,831

DRYER WITH TEMPERATURE VAHYING AIR FLOW RESTRICTION PLATE Original Filed Nov. 10, 1966 WITNESSES I INVENTOR fl/ 2M 4 Norma J. Workman.

AGENT United States Patent Int. Cl. F26b 21/06, 11/02 U.S. C]. 3482 4 Claims ABSTRACT OF THE DISCLOSURE Laundry apparatus for drying articles of clothing. The apparatus is characterized by the provision of means in the form of an orifice plate, remotely located from the interior of the drum forming a part of the apparatus, for selectively restricting the flow of air through the apparatus in order to raise the otherwise inadequate temperature thereof to a level suitable for drying certain types of clothing.

This is a continuation of applicants copending application, Ser. No. 593,470, filed Nov. 10, 1966 and now abandoned.

This invention relates, in general, to clothes drying apparatus and, more particularly, to apparatus suitable for drying Permanent Press garments or fabrics.

As is well known, clothes referred to as Permament Press garments are treated by special processes which render them highly resistant to wrinkling while being worn. Such garments, however, become quite wrinkled when laundered due to the wash water temperature and the compacting of the clothes against the wall of the spinner basket.

Such garments have what is called a built-in-memory such that wrinkles put into the garment at a specific temperature, for example, 140 F., are locked in and cannot be removed unless the garment temperature is again raised to that temperature as by use of a clothes dryer.

It will be apparent, therefore, that the wrinkles will not fall out at a lower temperature, for example 130 F. Consequently, dryers which operate at 130 F., i.e. those operating on 115 volts and some operating on 230 volts, are not suitable for drying such garments.

Accordingly, the general object of this invention is to provide a new and improved clothes dryer.

It is a more particular object of this invention to provide a new and improved clothes dryer which is suitable for use with Permanent Press garments.

Another object of this invention is to provide new and improved means for varying the operating temperature of a clothes dryer.

Briefly, the above-cited objects are accomplished by providing an orifice plate adapted to be selectively placed in the path of air flowing through a dryer. The orifice plate when installed serves to reduce the air flow rate a predetermined amount to thereby effect a rise in operating temperature of the dryer to that suitable for drying Permanent Press clothes.

Other objects and advantages of the present invention will become more apparent when considered in view of the following detailed description in which:

FIGURE 1 is a perspective view, partly broken away, of an electric dryer representing the invention; and

FIG. 2 is a perspective view of an air flow restriction device forming a part of the present invention, and shown inverted to illustrate its locating rib.

Referring now to the drawings, especially FIG. 1, reference character designates generally an electric clothes 3,475,831 Patented Nov. 4, 1969 "ice dryer comprising a clothes basket or drum 11 having a generally cylindrical shape and including an imperforate annular wall 12 and a perforate rear wall 13 opposite a front wall 14. The front wall 14 has an opening 16 providing access to the interior of the drum 11 for insertion or removal of clothes.

A bearing structure 17 carried by the rear wall 13 and an extended annular flange 18 framing the opening 16 serve to support the drum 11 for rotation about a substantially horizontal axis within a frame or cabinet 15. The

. drum 11 is rotated by means of a conventional motor 19 through a flat drive belt 20 encircling the annular wall 12 and a pulley fixed to one end of the output shaft of the motor 19.

The other end of the shaft is connected to air circulating means 21, the inlet side of which communicates with one end of the front baflie or air duct assembly 22 supported by a front wall 23 of the cabinet 15. The other end of the air duct 22 is provided with a lint trap 24 which serves to filter lint from the circulating air.

A door structure 26, only a fragment of which is shown, comprises an imperforate front wall 27 and a perforate rear wall 28 spaced from the front wall 27 by an annular wall 29. The lowermost portion of the annular wall 29 is provided with an elongated rectangular shaped aperture 31 which registers with the lint trap 24 when the door structure 26 is closed.

An electrical resistance heating structure 32 over which the circulating air must flow, serves to heat the air to accelerate removal of moisture from the clothes. A temperature control thermostat 33 allows operation of the heater 32 at about 130 F. when operating on volts AC. The dryer 10 is wired in a conventional manner, not shown, such that it also operates on a higher voltage, for example, 230 volts and, therefore, at a higher temperature than F. Consequently, the temperature control thermostat 33 effects cyclic operation of the heater 32 to maintain the operation at between -160 F.

While dryers of the type herein disclosed are wired for operation on either 115 or 230 volts and while they are usually connected to a supply voltage of 230 volts, it sometimes happens that by choice or otherwise, there is only 115 volts supplied to the dryer. It will be appreciated that in such a situation the dryer will not satisfactorily dry Permanent Press garments as the temperature will not reach 140 F.

In accordance with the present invention, therefore, there is provided an orifice plate or air flow restrictor 36 made from any high temperature plastic or other suitable material. The plate 36 has a generally rectangular shape and is provided on its underside with a rectangular shaped rib 37 which is received within an opening 38 in the lint trap 24 to align the plate 36 at the inlet side of the trap 24. The plate is provided with a pair of circular apertures 38 through which air flows when the plate is in use. The aperture sizes are so designed as to reduce the quantity of air flow from about 2000 feet per minute to about 937 feet per minute. This reduction causes the operating temperature to rise from about 130 F. to between ISO- F., a suitable temperature for drying Permanent Press garments. The temperature control 33 which is calibrated to cycle at approximately ISO-160 F. will prevent thermal runaway when the flow is so restricted.

It should be pointed out that the use of the present invention is not limited to dryers operating on 115 volts. Some dryers on the market do not reach proper temperature even when operated on 230 volts.

Since numerous changes may be made, in the abovedescribed apparatus and different embodiments of the invention may 'be made without departing from the spirit thereof, accordingly it is intended that all matter contained in the foregoing description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense. w w

I claim as my invention:

1. Dryer structure comprising: a drum supported in a cabinet for rotation about a substantially horizontal axis, said drum having an open end in registry with an opening in one wall of said cabinet, means for etfecting rotation of said drum, means for effecting circulation of air through said drum, air duct structure communicating with said air circulating means and said drum for conveying air therebetween, means for heating said circulating air adapted for operation at a first energy level, means for varying the operating temperature of said dryer when said air heating means is operated at said first energy level, said means for varying the operating temperature comprising means associated with said air duct structure for restricting air flow therethrough, a lint trap disposed in said air duct structure, said air fiow restricting means comprising an orifice plate supported by said lint trap.

2. Structure as specified in claim 1, wherein, said orifice plate is removably supported by said lint trap.

3. Dryer structure comprising, a drum supported in a cabinet for rotation about a substantially horizontal axis, said drum having an open end in registry with an opening in one wall of said cabinet, means for effecting rotation of said drum, means for effecting circulation of air through said drum, air duct structure communicating with said air circulating means and said drum for conveying air therebetween, means for heating said circulating air adapted for operation at two energy levels including a relatively high and a relatively low level, and means remote from said drum for selectively varying the operating temperature of .said dryer, when said air heating means is operated at either of said energy levels, said means for varying the operating temperature comprising means-associated with said air duct structure for restricting flow therethrough, a lint trap disposed in said air duct structure, said air tlow restricting means comprising an orifice plate supported by said lint trap.

4. Structure as specified in claim 3 wherein said orifice plate is removably supported by said lint trap.

References Cited UNITED STATES PATENTS 2,970,383 2/1961 Hughes 34-54 XR 3,071,864 1/1963 Menk 34-54 XR CARLTON R. CROYLE, Primary Examiner A. D. HERRMANN, Assistant Examiner US. Cl. X.R. 

